intel cache-as-ram: Unify stack setup

No need to have %ebx reserved here.

Change-Id: I9fe9292ddc610079b876019a71c69af5b1bcf2a2
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/17357
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/cpu/intel/model_206ax/cache_as_ram.inc

@@ -178,7 +178,7 @@ before_romstage:
 	/* Save return value from romstage_main. It contains the stack to use
 	 * after cache-as-ram is torn down.
 	 */
-	movl	%eax, %ebx
+	movl	%eax, %esp
 
 	post_code(0x30)
 
@@ -285,11 +285,7 @@ before_romstage:
 __main:
 	post_code(POST_PREPARE_RAMSTAGE)
 	cld			/* Clear direction flag. */
-
-	/* Setup stack as indicated by return value from romstage_main(). */
-	movl	%ebx, %esp
-	movl	%esp, %ebp
-	call	copy_and_run
+	call	romstage_after_car
 
 .Lhlt:
 	post_code(POST_DEAD_CODE)